1. Field of the Invention
The present invention relates to an apparatus which can read a document at a desirable magnification.
2. Description of the Prior Art
In an image reader, the density of a document is read with an image sensor and is sent to an external output apparatus such as a printer after being transformed into bi-level data.
In a conventional image reader, the magnification for reading is varied by processing signals electrically.
In the electrical variation of magnification, image signals from the image sensor are processed electrically so as to enlarge or reduce the image, while the resolution of reading by the image sensor is kept unchanged.
An essential disadvantage in the electrical variation is that an output image is made coarse upon enlarging the image at high magnification because it is enlarged without heightening the resolution of reading.